The preparation of laminated composites employing various polymeric substrate compositions for use as printed circuit boards or for other uses such as corrosion resistant layers, paneling, decorative structures and the like are well known. The polymeric substrates commonly used are the epoxide resin-base materials, triazine resins and polyimide resins for circuit board laminates. Synthetic resin glues such as urea-formaldehydeor phenol-formaldehyde resin in water have been employed in the preparation of wood laminates.
As will hereinafter be set forth in greater detail, it has been discovered that in addition to the preparation of a metal clad laminate for printed circuit boards, which have excellent electrical properties which exceed those required by U.S. Military Specification (MIL-P-13949F), other laminates containing the rigid polyurethane modified polyisocyanurate of the present invention and at least one layer of wood or cellulosic material, plastic, glass, or a ceramic sheet or combinations thereof may be prepared in a compression mold for use in many areas of the construction, building, packaging automotive, electronics, etc. industries.
U.S. Pat. No. 4,623,577 describes a circuit board laminate made from a cross linked polycyanurate polymer and a thermoplastic polymer such as a polyethersulfone and polycarbonate, and a polyaramid fiber.
U.S. Pat. No. 4,562,119 discloses a laminate comprising a central core of cellulosic or mica filler and a thermosetting resin and skin laminae of glass, asbestos or heat stable synthetic polymer reinforcing filler and resin impregnant to which a metal foil is adhered.
Various laminated composites especially for printed circuit boards are also described in U.S. Pat. Nos. 4,671,984, 4,615,945, 4,526,835, 4,520,067, 4,511,757 and 4,492,730.